Achalasia is a rare motor disorder of the gastroesophageal junction which is associated with an increased pressure of the esophageal sphincter. This leads to impairment to swallow and heartburn. Esophageal myotomy, which is a surgical longitudinal incision of the esophageal muscle layer extending over to the gastroesophageal junction is the treatment of choice for achalasia. In order to prevent reflux of stomach content into the esophagus this has to be combined with an antireflux procedure where the upper part of the stomach (fundus) is wrapped around the esophagus (fundoplication). This procedure can be performed with the wrapped fundus either in front of the esophagus (Dor procedure) or behind (Toupet). The latter introduces an angulation of the esophagus, which possibly may lead to an impairment of swallowing ability and passage of food to the stomach. On the other hand, the Toupet procedure may give a better control of reflux. The primary endpoint of the study is symptoms of impaired swallowing 1 year after treatment. Secondary outcomes include reflux (pH measurements in the esophagus), radiological imaging of swallowing and quality of life.